Official ESP-IDF framework support

[Thomasdezeeuw]

Initial request in #1691, initial addition in #1692.

Requirements:

• Committed maintainer(s).
• Some sort of CI support, preferably cargo test, cargo check will do.

To do after:

• Document specifics, e.g. in Poll and Event.
• Document supported versions (we don't do this properly yet, might as well start at some point).

[Thomasdezeeuw]

I think we can add basic CI support by adding the target to:

mio/.github/workflows/ci.yml

Line 145 in 2d7b454

target: ["aarch64-apple-ios", "aarch64-apple-tvos", "aarch64-unknown-openbsd", "arm64_32-apple-watchos", "armv7-sony-vita-newlibeabihf", "sparcv9-sun-solaris", "x86_64-pc-solaris", "x86_64-unknown-dragonfly", "x86_64-unknown-openbsd"]

[dignifiedquire]

trying to compile mio@8.10 for espidf, and getting these compiler issues, is this expected?

error[E0432]: unresolved imports `self::selector::event`, `self::selector::Event`, `self::selector::Events`, `self::selector::Selector`
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/mod.rs:18:37
   |
18 | ...selector::{event, Event, Events, Selector};
   |               ^^^^^  ^^^^^  ^^^^^^  ^^^^^^^^ no `Selector` in `sys::unix::selector`
   |               |      |      |
   |               |      |      no `Events` in `sys::unix::selector`
   |               |      no `Event` in `sys::unix::selector`
   |               no `event` in `sys::unix::selector`
   |
   = help: consider importing this module instead:
           crate::event
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:21:30
   |
21 | pub(crate) use self::epoll::{event, Event, Events, Selector};
   |                              ^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:35:29
   |
35 | pub(crate) use self::poll::{event, Event, Events, Selector};
   |                             ^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:70:31
   |
70 | pub(crate) use self::kqueue::{event, Event, Events, Selector};
   |                               ^^^^^
   = help: consider importing this struct through its public re-export instead:
           crate::event::Event
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:21:37
   |
21 | pub(crate) use self::epoll::{event, Event, Events, Selector};
   |                                     ^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:35:36
   |
35 | pub(crate) use self::poll::{event, Event, Events, Selector};
   |                                    ^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:70:38
   |
70 | pub(crate) use self::kqueue::{event, Event, Events, Selector};
   |                                      ^^^^^
   = help: consider importing this struct through its public re-export instead:
           crate::Events
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:21:44
   |
21 | pub(crate) use self::epoll::{event, Event, Events, Selector};
   |                                            ^^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:35:43
   |
35 | pub(crate) use self::poll::{event, Event, Events, Selector};
   |                                           ^^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:70:45
   |
70 | pub(crate) use self::kqueue::{event, Event, Events, Selector};
   |                                             ^^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:21:52
   |
21 | pub(crate) use self::epoll::{event, Event, Events, Selector};
   |                                                    ^^^^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:35:51
   |
35 | pub(crate) use self::poll::{event, Event, Events, Selector};
   |                                                   ^^^^^^^^
note: found an item that was configured out
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/selector/mod.rs:70:53
   |
70 | pub(crate) use self::kqueue::{event, Event, Events, Selector};
   |                                                     ^^^^^^^^

error[E0412]: cannot find type `WakerInternal` in this scope
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/waker.rs:38:16
   |
38 |         waker: WakerInternal,
   |                ^^^^^^^^^^^^^ not found in this scope
   |
help: consider importing this struct
   |
31 +     use crate::sys::unix::waker::eventfd::WakerInternal;
   |

error[E0433]: failed to resolve: use of undeclared type `WakerInternal`
  --> /Users/dignifiedquire/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mio-0.8.10/src/sys/unix/waker.rs:43:25
   |
43 |             let waker = WakerInternal::new()?;
   |                         ^^^^^^^^^^^^^ use of undeclared type `WakerInternal`
   |
help: consider importing this struct
   |
31 +     use crate::sys::unix::waker::eventfd::WakerInternal;
   |```

[dignifiedquire]

Sorry for the noise, I was missing RUSTFLAGS="--cfg mio_unsupported_force_poll_poll"